In a Support document published this week, Apple acknowledged the Flashback malware threat and promised to offer software that will keep users out of harm’s way. Customers running older versions of Mac OS X were advised to disable their Java plug-in as a temporary resolution.
A KB article
on Apple Support explains that in order to disable the Java web plug-in in Safari, customers must follow these steps:
1. In Safari, choose Safari > Preferences or press Command-comma (⌘-,)
2. Click "Security".
3. Uncheck (deselect) "Enable Java".
4. Close the Safari preferences window.
Apple also provides instructions for disabling Java in Chrome